A streak camera is an apparatus having a camera for image-sensing the output surface of a streak tube. A streak apparatus having a streak tube is an apparatus for converting the intensity distribution of measurement target light over time into a spatial intensity distribution on an output surface. For example, Japanese Patent Publication No. 4-73257 discloses an electromagnetic focusing streak apparatus. This streak apparatus has a single focusing magnetic flux generator (electromagnetic focusing coil). The focusing magnetic flux generator generates a focusing magnetic flux in only a space between a photocathode and the input of a deflecting electrode from the outside of a streak tube, to substantially focus photoelectrons emitted from the photocathode.